食管癌Egr-1基因表达及其与细胞凋亡的关系

目的：研究早期生长反应基因-1（Egr-1基因）和Bcl-X1蛋白在人食管癌变过程中的表达及与细胞凋亡的关系。方法：应用原位杂交、免疫组织化学和TUNEL法检测66例食管鳞状细胞癌及癌旁粘膜、上切缘粘膜中Egr-1mRNA和蛋白、凋亡相关蛋白Bcl-X1和原位细胞凋亡。结果：食管上皮和食管癌细胞Egr-1基因原位杂交、Bcl-X1.蛋白免疫组化阳性物定位于细胞浆,Egr-1蛋白免疫组化阳性产物、TUNEL法阳性信号定位于细胞核。在食管癌变过程中,细胞凋亡发生率和凋亡指数逐渐升高;Egr-1mRNA及蛋白在食管粘膜上皮非典型增生中呈高表达。在癌组织,Egr-1阳性表达时凋亡指数显著高于其阴性表达;而Bcl-X1.阳性表达时凋亡指数显著低于其阴性表达。结论：细胞凋亡发生在食管癌变的全过程。Egr-1mRNA和蛋白在食管癌前病变呈高表达;Egr-1阳性鳞癌的凋亡指数显著升高;Egr-1有促进凋亡的作用。Egr-1的表达和细胞凋亡在食管癌变过程中可能有重要生物学意义。     

Cdc25C在放疗敏感的食管鳞状细胞癌中高表达

目的研究食管鳞状细胞癌组织中Cdc25C的表达与放疗敏感性的关系。方法回顾性分析62例根治性放疗的局部晚期食管鳞状细胞癌患者,根据放疗近期疗效分为放疗敏感组和放疗不敏感组,采用免疫组织化学检测放疗前食管癌组织中Cdc25C表达,分析Cdc25C的表达与放疗敏感性之间的关系。结果食管鳞状细胞癌组织中Cdc25C表达率显著高于癌旁正常上皮组织,放疗敏感组Cdc25C表达率显著高于放疗不敏感组。结论食管鳞状细胞癌组织中Cdc25C高表达与放疗敏感性密切相关,Cdc25C的高表达可能有助于预测肿瘤细胞对放射治疗的敏感性,对于指导食管鳞状细胞癌临床治疗具有重要的参考意义。     

P16、P27蛋白在食管鳞状细胞癌中的表达及意义

目的为探讨P16、P27蛋白在食管鳞状上皮、增生上皮和癌变上皮中表达状况及其与鳞状细胞癌发生、进展和转移的相关性.方法采用SP免疫组织化学方法,检测72例(其中活检标本13例)食管癌组织中P16、P27蛋白的表达情况.结果 P16、P27在食管癌和增生性上皮均有阳性表达,但两者相比均无统计学意义(P>0.05),在正常上皮组均无阳性表达;P16、P27在高分化鳞癌组阳性表达率均显著高于低分化鳞癌组(P<0.05);P16、P27在伴有淋巴结转移的食管癌组与不伴有淋巴结转移组比较差异显著(P<0.05).P16在原发食管癌组阳性表达率和淋巴结转移癌中比较具有显著性差异(P<0.05).结论 P16、P27基因蛋白在食管癌组织中的表达与病理分化程度有关;P16的表达与转移癌的形成有关;P16、P27表达与患者性别、年龄、肿瘤发生部位、浸润深度无明显相关性.     

食管癌前细胞DNA、端粒酶含量及多基因表达产物的定量检测

为探讨食管癌高发区人群食管上皮癌变过程中的早期分子改变及早期癌变机理.应用流式细胞术和免疫荧光技术及碘化丙啶DNA荧光染色方法,对食管上皮癌前细胞的DNA含量、端粒酶含量和多个基因p53、p16、cyclin D1蛋白质表达进行了定量检测.检测结果发现,DNA含量在癌变形成时明显增加,异倍体率为87.9%;p53蛋白积聚发生在癌变早期,在癌细胞组的阳性率为100%（5/5）;抑癌基因p16在癌变早期有明显缺失;癌基因cyclin D1及端粒酶阳性率在癌细胞组都为100%（分别为6/6,7/7）.研究结果表明：在癌变早期,DNA含量及异倍体率增加,癌基因cyclin D1表达增高,抑癌基因p16缺失及p53蛋白积聚,端粒酶含量也明显增高,在癌形成时已有多个分子事件发生.     

DcR3蛋白在人食管鳞状细胞癌中的表达及临床意义

目的:探讨诱骗受体(Decoy receptor 3,Dc R3)蛋白在人食管鳞状细胞癌中的表达和临床意义。方法:通过免疫组化的方法,在人食管鳞状细胞癌组织和正常食管粘膜组织各112例中检测Dc R3蛋白的表达差异,并分析Dc R3蛋白表达与食管鳞状细胞癌临床病理学特征间的相关性。结果:在组织标本中检测发现,Dc R3蛋白在食管鳞状细胞癌组织中的阳性表达为72.3%,在正常食管粘膜组织中的阳性表达为25.9%。卡方检验分析表明,Dc R3蛋白在食管鳞状细胞癌组织中的阳性表达与食管鳞状细胞癌的临床分级(P=0.002)、淋巴结转移(P0.001)、组织学分级(P=0.01)具有显著相关性,而与患者的年龄(P=0.673)、性别(P=0.378)、抽烟史(P=0.392)、饮酒史(P=0.093)等均无关。Spearman相关性分析检测发现,Dc R3蛋白高表达与高临床分级(r=-0.213,P=0.024)、高组织学分级(r=-0.285,P=0.002)、淋巴结转移(r=-0.568,0.001)呈正相关,而与食管鳞状细胞癌患者的年龄、性别、吸烟史、饮酒史等均无相关性(P0.05)。结论:Dc R3蛋白在食管鳞状细胞癌组织中表达更高,且与食管鳞状细胞癌疾病的进展、转移呈正相关。Dc R3蛋白表达可用来检测食管鳞状细胞癌疾病严重程度。     

食管鳞状细胞癌癌组织中hMLH1、hMSH2的表达及其意义

目的:探讨错配修复基因hMSH2、hMLH1在食管鳞癌组织中的表达及其临床意义。方法:采用sP免疫组化的方法检测144例食管鳞癌手术切除标本、30例正常粘膜组织中hMSH2、hMLH1表达情况,并与临床病理参数作相关分析。结果:食管鳞癌组织hMSH2、hMLH1基因阳性表达明显下降,与正常食道粘膜相比相差显著(P<0.01),hMSH2、hMLH1表达缺失与年龄、性别、肿瘤大小、淋巴结转移、浸润深度无显著相关,与肿瘤的分化程度有关(P<0.01)。结论:提示hMLH1和hMSH2基因突变所致的蛋白表达异常缺失与食管鳞状细胞癌发生有关,可能为一种早期事件。     

缺氧/复氧对培养的大鼠海马神经元Fos、Jun表达和神经元凋亡的影响

目的：观察缺氧／复氧对体外培养的海马神经元Fos和Jun表达和神经元凋亡的影响。方法：取培养12d的海马神经元,置2000cm^3的恒温（36℃）密闭容器内,连续充以无氧气体（90％N2、10％CO2）,在缺氧条件下继续培养2、4h后取出,置含10％CO2和空气的培养箱内复氧培养24h和72h。于不同时间取出,观察神经元存活数,分别用抗Fos和抗Jun抗血清进行免疫组织化学染色,计数Fos和Jun表达阳性神经元百分率,并用原位末端标记（TUNEL）法和流式细胞术分别观察和测定缺氧／复氧对体外培养海马神经元凋亡的影响。结果：缺氧／复氧后Fos和Jun表达阳性神经元百分率和凋亡神经元百分率的显著增加。结论：缺氧／复氧后即早反应基因fos在神经元中的持续表达可引起神经元凋亡,原癌基因jun的表达与神经元凋亡的发生有关。     

MYC、PTEN和TP53表达与哈萨克族食管癌相关性研究

[目的]检测MYC、PTEN、TP53在哈萨克族食管癌组织和远端无癌组织的表达,分析与临床病理因素的关系,探讨它们在哈萨克族食管癌发生发展中可能存在的关系。[方法]Trizol一步法获取组织标本总RNA,逆转录为c DNA,运用半定量RT-PCR技术检测食管癌组织、远端无癌组织中三个基因mRNA表达量及阳性表达率。[结果]1 MYC mRNA表达量在食管癌组织中高于远端无癌组织(P0.01);PTEN、TP53 mRNA表达量在远端无癌组织中高于癌组织(P0.01,P0.05);2 MYC阳性表达率在食管癌组织中高于远端无癌组织(P0.01);PTEN、TP53阳性表达率在远端无癌组织中高于癌组织(P0.01,P0.05));3MYC表达与分化程度(P0.05)、TNM分期(P0.05)、淋巴结转移(P0.01)和侵犯深度(P0.05)有关;PTEN表达与分化程度有关(P0.05);TP53的表达与上述指标无关;4 MYC和PTEN、TP53表达呈负相关(r=-0.494;r=-0.428);PTEN、TP53表达呈正相关(r=0.531)。[结论]哈萨克族食管癌组织中MYC表达上调,PTEN、TP53低表达或不表达。上述结果说明MYC参与哈萨克族食管癌的发生和发展,PTEN、TP53则是阻止食管组织发生癌变的保护性基因。     

MicroRNA-21与平滑肌蛋白22α在哈萨克族食管癌组织中的表达及其临床病理学意义

目的探讨microRNA21与SM22a基因在哈萨克族食管癌发生发展中的作用及临床意义。方法免疫组织化学法检测162例石蜡包埋食管鳞状细胞癌组织及RT-PCR方法检测47例哈萨克族食管癌标本中microRNA21、SM22a表达水平,分析这些基因与临床病理特征的关系。结果SM22a在162例食管鳞癌组织中的阳性表达率(87.0%)显著高于食管正常黏膜组织(36.0%);在47例哈萨克族食管癌组织中,SM22a表达水平较远端无癌组织增高。与远端无癌组织相比,microRNA21在哈萨克族食管癌组织中表达水平增高。MicroRNA21高表达与分化程度、淋巴结转移、临床分期相关,SM22a高表达与临床分期相关、淋巴结转移相关;microRNA21与SM22a的表达呈正相关。结论MicroRNA21、SM22a协同高表达共同参与哈萨克族食管癌的侵袭发展过程。     

Immunohistochemical analysis for cell proliferation-related protein expression in small cell carcinoma of the esophagus; a comparative study with small cell carcinoma of the lung and squamous cell carcinoma of the esophagus

Small cell carcinoma is a rare neoplasm in the esophagus. To evaluate cell proliferation activity and its underlying mechanisms in this tumor, we examined immunohistochemically 5 cases of small cell carcinoma of the esophagus (SCCE) for expressions of tumor suppressor proteins, oncoproteins and cell proliferation markers including p53, p21WAF1/CIP1, retinoblastoma (Rb) protein, bcl-2, Ki-67 and PCNA, and compared the results with those of 5 cases of small cell carcinoma of the lung (SCCL) and 10 cases of squamous cell carcinoma of the esophagus (SQCE). The prevalence and labeling index of p53-immunoreactivity tended to be higher in SCCE (4/5; 56.6%) and SCCL (4/5; 79.9%) than in SQCE (6/10; 48.8%). Expression of p21WAF1/CIP1 was observed in 2 of 10 cases of SQCE. In contrast, its expression could not be detected in any cases of SCCE and SCCL examined. Expression of Rb protein was observed in 9 out of 10 cases of SQCE, but not in any cases of SCCE and SCCL. SCCE and SCCL showed more frequent and intense immunoreactivity for bcl-2 than SQCE. In expression of cell proliferation markers (Ki-67 and PCNA), no remarkable difference was observed among SCCE, SCCL and SQCE. These results suggest that SCCE and SCCL could share some genetic alternations including mutation of p53, loss of Rb gene and overexpression of bcl-2, and these may be related to the similar biological potentials between the two. Furthermore, SCCE was different from SQCE in expression of Rb protein and bcl-2, and these two types of esophageal carcinoma could arise through different molecular mechanisms.     

p27和p53基因在大肠癌中的表达及临床意义

目的 研究大肠癌患者癌组织中p27、p53基因的表达及其相互之间的关系,以探讨p27、p53基因在大肠癌发生中的作用及临床意义。方法 运用原位杂交方法及免疫组化SP法检测58例大肠癌组织及正常黏膜中p27mRNA和P27蛋白的表达,同时运用免疫组化法分析相同组织中P53蛋白表达状况。结果 p27mRNA在大肠癌组织及正常黏膜中的表达阳性率均为100%。P27蛋白在大肠癌组织中的表达阳性率为55.17%,在正常黏膜中的表达阳性率为96.55%（P〈0.01）;癌组织中P53蛋白表达阳性率为53.45%,正常黏膜未见P53蛋白表达（P〈0.01）;大肠癌组织中P27与P53蛋白表达无明显相关性。P27蛋白的表达与肿瘤分化程度呈负相关（P〈0.01）,与临床其它病理因素均无相关性（P〉0.05）。大肠癌组织中P53蛋白表达与临床病理因素亦无相关性（P〉0.05）。结论 P27蛋白表达的调控主要在转录后水平,P27蛋白检测可作为评价大肠癌恶性程度和预后判断的重要指标。P27及P53蛋白在大肠癌的发生发展过程中具有重要作用。     

Differential p53 phosphorylation and activation of apoptosis-promoting genes Bax and Fas/APO-1 by irradiation and ara-C treatment

In this study, we examined the effects of radiation and ara-C on induction of apoptosis and on the apoptosis-promoting genes p53, Bax and Fas/APO-1, in BV173 human leukemia cells, which harbor the wild-type p53 gene. It has been reported that p53 upregulates Fas/APO-1 and Bax expression. Both irradiation and ara-C treatment resulted in apoptosis and induction of p53 proteins within hours. The Bax gene was activated in irradiated and ara-C-treated BV173 cells, but Fas/APO-1 was induced only in irradiated BV173 cells. Radiation and ara-C treatment did not induce Bax or Fas/APO-1 protein expression in p53-null HL60 cells. Radiation weakly induced Fas/APO-1 expression in KBM-7 cells, which harbor a partially defective p53 gene. Both HL60 and KBM-7 cells are more resistant to radiation- and ara-C-induced apoptosis than BV173 cells. These results suggest that functional p53 is necessary for the activation of Bax and Fas/APO-1 expression. However, elevated p53 protein is not sufficient to activate Fas/APO-1 gene expression in ara-C-treated cells. Using two-dimensional gel electrophoresis, we found that the p53 proteins in irradiated and ara-C-treated BV173 cells have different isoelectric points; they converged to a single isoelectric point after in vitro treatment with phosphatase. These results suggest that different genotoxic treatments cause different phosphorylations of p53, which may account for the different levels of activation of Fas/APO-1 expression.     

非小细胞肺癌中细胞凋亡与P53、Bcl-2蛋白的表达及对预后的影响

目的研究细胞凋亡及凋亡相关蛋白P53和Bcl-2在非小细胞肺癌组织中的表达水平,及其对预后的影响。方法应用DNA缺口末端标记技术和免疫组化方法检测111例肺癌患者组织中细胞凋亡、突变型P53和Bcl-2蛋白表达水平。结果111例肺癌中,细胞凋亡高表达53例(47.7%),突变型P53蛋白阳性45例(40.5%),Bcl-2蛋白阳性59例(53.2%)。COX模型多因素分析显示,淋巴结的转移和Bcl-2蛋白的阳性表达是本组肺癌患者的预后不良因素(P<0.05)。结论凋亡及凋亡相关蛋白P53和Bcl-2影响肺癌患者的生物学行为及预后。     

Ionizing radiation down-regulates p53 protein in primary Egr-1-/- mouse embryonic fibroblast cells causing enhanced resistance to apoptosis

In this study, we sought to investigate the mechanism of the proapoptotic function of Egr-1 in relation to p53 status in normal isogenic cell backgrounds by using primary MEF cells established from homozygous (Egr-1(-/-)) and heterozygous (Egr-1(+/-)) Egr-1 knock-out mice. Ionizing radiation caused significantly enhanced apoptosis in Egr-1(+/-) cells (22.8%; p < 0.0001) when compared with Egr-1(-/-) cells (3.5%). Radiation elevated p53 protein in Egr-1(+/-) cells in 3-6 h. However, in Egr-1(-/-) cells, the p53 protein was down-regulated 1 h after radiation and was completely degraded at the later time points. Radiation elevated the p53-CAT activity in Egr-1(+/-) cells but not in Egr-1(-/-) cells. Interestingly, transient overexpression of EGR-1 in p53(-/-) MEF cells caused marginal induction of radiation-induced apoptosis when compared with p53(+/+) MEF cells. Together, these results indicate that Egr-1 may transregulate p53, and both EGR-1 and p53 functions are essential to mediate radiation-induced apoptosis. Rb, an Egr-1 target gene, forms a trimeric complex with p53 and MDM2 to prevent MDM2-mediated p53 degradation. Low levels of Rb including hypophosphorylated forms were observed in Egr-1(-/-) MEF cells before and after radiation when compared with the levels observed in Egr-1(+/-) cells. Elevated amounts of the p53-MDM2 complex and low amounts of Rb-MDM-2 complex were observed in Egr-1(-/-) cells after radiation. Because of a reduction in Rb binding to MDM2 and an increase in MDM2 binding with p53, p53 is directly degraded by MDM2, and this leads to inactivation of the p53-mediated apoptotic pathway in Egr-1(-/-) MEF cells. Thus, the proapoptotic function of Egr-1 may involve the mediation of Rb protein that is essential to overcome the antiapoptotic function of MDM2 on p53.